Go for it just test drive a few. As mentioned don't buy a saloon car conversion but a sports one only.
Had 2 x MR2's 1x 350z ragtop naturally and now a mk3 MX5. Love them all for different reasons but you can't beat that sensation of wind in the hair motoring. Never had any bad comments, sneers or hairdresser remarks even in the MX5 Which has surprised me how good it really is. Autumn and winter are my favourite top down driving days, find summer a bit boring really generally your breathing in diesel fumes from a wagon etc!
Never had bird poo or anyone spit at me and if you drive above a certain speed the rain goes over the top anyway, it's the water off the wipers that gets you in a rainstorm.
No roof problems or leaks at all. Buy an MR2 roadster for about 4k or mk1 MX5 for 1500.
Good luck with your search